US3327347A - Extruder for processing solid thermoplastics - Google Patents

Extruder for processing solid thermoplastics Download PDF

Info

Publication number
US3327347A
US3327347A US493099A US49309965A US3327347A US 3327347 A US3327347 A US 3327347A US 493099 A US493099 A US 493099A US 49309965 A US49309965 A US 49309965A US 3327347 A US3327347 A US 3327347A
Authority
US
United States
Prior art keywords
screw
feed inlet
pocket
extruder
inlet means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US493099A
Inventor
Schippers Heinz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oerlikon Barmag AG
Original Assignee
Barmag Barmer Maschinenfabrik AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Barmag Barmer Maschinenfabrik AG filed Critical Barmag Barmer Maschinenfabrik AG
Application granted granted Critical
Publication of US3327347A publication Critical patent/US3327347A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/22—Extrusion presses; Dies therefor
    • B30B11/24—Extrusion presses; Dies therefor using screws or worms
    • B30B11/248—Means preventing the material from turning with the screw or returning towards the feed hopper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/501—Extruder feed section
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion

Definitions

  • thermoplastics will be referred to hereinafter only as non-fluid.
  • this invention relates to a single-screw extruder of non-fluid pulverous thermoplastics, having an entrance pocket in the feeding zone of the screw.
  • the device of this invention is a singlescrew extruder of non-fluid thermoplastic pulverous material comprising a screw jacket means having an inlet end, and extruder screw disposed within said jacket means, and a plastic material feed inlet means communicating with the inlet end of said jacket means.
  • the inside width of the feed inlet has a size substantially at least as large as the diameter of the extruder screw.
  • the inner surface of the jacket means defines an entrance pocket extending from said feed inlet means for at least the length of a simple screw pitch in the axial direction or conveying of the screw.
  • the entrance pocket has its greatest crosssectional area adjacent the feed inlet. The radial distance from the upper edge of the screw thread to the upper surface of the pocket decreases constantly from adjacent the feed inlet means in the conveying direction away from the feed inlet.
  • the screw extruder of this invention has an axial entrance pocket for the processing of thermo- Patented June 27, 1967 plastic synthetics which are fed to the inlet zone of the screw in a solid state of aggregation.
  • the device of this invention is particularly suitable for processing plastics in a non-fluid form such as powders, chips, slices or other particles of low bulk weight. In order to ensure a reliable conveyance of the feed material to the screw, it is necessary that the latter be tightly enclosed in the entrance zone by the wall of the cylinder along a circular arc of from at least 180 to 270.
  • the material fed to the extruder is pressed into the screw threads under the shearing, peeling and wedging effect of the entrance pocket and is subsequently transported immediately under force into the space enclosed by the cylinder wall.
  • the screw threads are thereby completely filled.
  • the largest cross-section of the entrance pocket is adjacent the filling port and is within the legs of a sector angle having the screw axis as its vertex, this angle being less than 180 and preferably from 45 to
  • this device eliminates the difliculties in the feeding and conveying process in a completely satisfactory manner, even when processing extremely pulverulent, powder-like material having a very low bulk weight.
  • Suificiently high pressures can be obtained in the cylinder of the screw extruder without a special feed screw or a double screw arrangement, thus avoiding many disadvantages which are present in previously known devices.
  • the inside width of the feed inlet approximately equal to or larger than the diameter of the screw, and preferably to provide an agitating device such as a stirrer in the feed inlet.
  • FIGURE 1 shows a longitudinal section through the feed inlet zone and the portions of the screw extruder joining this zone on the left and on the right;
  • FIGURES 2 through 4 illustrate various cross-sectional shapes according to section 22 of FIGURE 1;
  • FIGURE 5 shows a further possible cross-sectional shape along section 5-5 of FIGURE 1;
  • FIGURES 6 through 11 show various positions and constructions of the entrance pocket
  • FIGURE 12 is a longitudinal section of an extruder with an agitator in the feed inlet.
  • the screw 3 is provided in the cylinder 1 which has a feed inlet 2.
  • the cylinder section joining the entrance port is provided, according to this invention, with an entrance pocket 4 gradually tapering in the conveying direction.
  • the radial distance between the upper surface of the entrance pocket defined by the screw jacket and the screw thread decreases constantly in the conveying direction, away from the feed inlet.
  • the breadth and height, as well as the length and/ or the slope of the upper surface of this axial entrance pocket can be specially adjusted to the bulk weight and flow properties of the material to be processed and to the friction between the contacting, loose particles of the plastic material.
  • the length of the pocket determined by the angle of inclination with respect to the screw axis, is of particular importance. This length should extend along several screw threads.
  • the wall of the pocket can be a segment of a cylinder as shown in FIG- URES 6, 7 and 10, or a segment of a cone as shown in FIGURES 8, 9 and 11.
  • the recess defined by the screw cylinder wall 1 can have the shape of a cylinder or cone having an axis which intersects the screw axis as shown in FIGURES 6, 7, 8, and 9, or which is askew therewith in the direction of rotation of the screw as shown in FIG- URES 10 and 11.
  • the decrease in volume of the entrance pocket in the direction of the screw axis or the conveying path can be adapted to the bulk weight of the plastic, and the axial direction of the recess can be adapted to the fluidity of the feed material.
  • the decrease in volume can be increased for larger material bulk weights.
  • the longitudinal dihedral angle between the screw axis and the axial direction of the recess can be increased for less fluid material.
  • the feed material conveyed by the first screw threads along the circumference thereof into the axial entrance pocket is pressed into the screw threads under the wedge effect of the pocket wall inclined toward the screw axis.
  • the excess material swept aside at the cylinder wall is pressed into the screw thread sections which are only partially filled. For example, if the filling zone is completely filled an accumulation of material can be observed in the entrance pocket adapted to the inclined wall and having a tendency to move at right angles to the screw axis or backward. This accumulation is continuously depleted, but is increased again to the same extent by newly arriving material.
  • the inlet zone of the conveyor screw is extended along a relatively large distance in the axial direction, for at least the distance of two simple screw pitches. Thereby several screw threads are always simultaneously in a position to entrain the raw material, to conveyor the same into the cylinder space, and in this manner, to produce the pressure necessary for extruding the mass.
  • FIGURE 12 shows the screw extruder of this invention with an agitation device such as a stirrer for facilitating feeding of very low density powders into the extruder feed inlet 2.
  • an agitation device such as a stirrer for facilitating feeding of very low density powders into the extruder feed inlet 2.
  • Ascrew extruder for the processing of non-freeflowing pulverous plastic solids of low bulkweight comprising a screw jacket means having an inlet end, an extruder screw disposed within said jacket means, a plastic material feed inlet means communicating with the inlet end of said jacket means, the inside width of said feed inlet having a size substantially at least as large as the diameter of the extruder screw, and an entrance pocket defined by the inner surface of the jacket means, said pocket extending from said feed inlet means for at least the length of a simple screw pitch in the axial direction of the screw, said pocket having its greatest cross-sectional area adjacent the feed inlet means, and the radial distance from the upper edge of the screw thread to the upper surface of the pocket decreasing constantly from adjacent the feed inlet means in the direction away from the feed inlet means; wherein the largest cross-sectional area of the entrance pocket adjacent the feed inlet means is within the legs of a sector angle having the screw axis as its vertex, the sector angle being within the range of from to 2.
  • the screw extruder of claim 1 comprising an agitation means extending into the feed inlet means.

Description

June 27, 1967 H. SCHIPFERS 3,327,347
EXTRUDER FOR PROCESSING SOLID THERMOPLASTICS Filed 001:. 5, 1965 FIG .II
INVENTOR. Heinz Schlppers ATTORN Y United States Patent 3,327,347 EXTRUDER FOR PROCESSING SOLID THERMGPLASTICS Heinz Schippers, Rernscheid-Lennep, Germany, assignor to Banner Maschinenfabrik Aktiengesellschaft, Wuppertal-Oberbarmen, Germany Filed Oct. 5, 1965, Ser. No. 493,099 Claims priority, application Germany, May 29, 1965, B 82,168 5 Claims. (Cl. 125-12) The present invention relates to an extruder for processing solid thermoplastics, particularly of small pulverized sizes, having a very low bulkweight and surface characteristics preventing their spontaneous free flow under conditions of gravity.
For the purposes of this disclosure, these thermoplastics will be referred to hereinafter only as non-fluid. In particular, this invention relates to a single-screw extruder of non-fluid pulverous thermoplastics, having an entrance pocket in the feeding zone of the screw.
In summary, the device of this invention is a singlescrew extruder of non-fluid thermoplastic pulverous material comprising a screw jacket means having an inlet end, and extruder screw disposed within said jacket means, and a plastic material feed inlet means communicating with the inlet end of said jacket means. The inside width of the feed inlet has a size substantially at least as large as the diameter of the extruder screw. The inner surface of the jacket means defines an entrance pocket extending from said feed inlet means for at least the length of a simple screw pitch in the axial direction or conveying of the screw. The entrance pocket has its greatest crosssectional area adjacent the feed inlet. The radial distance from the upper edge of the screw thread to the upper surface of the pocket decreases constantly from adjacent the feed inlet means in the conveying direction away from the feed inlet.
In copending application Ser. No. 492,518 for a Plastic Melt Extruder, filed by Guenter Roehlig and Guenter Augustin on Oct. 4, 1964, and owned by the assignee of this application, an axially extending entrance pocket for a screw extruder for processing thermoplastics, resins is disclosed. Therein the raw material is fed to the screw in a fluid or plasticized state, i.e., from a viscous to a highly fluid form, for example in a honeylike consistency. With the entrance pocket, complete filling of the screw threads in the cylinder is obtained, and sufiiciently high pressures can be achieved for flawless and reliable processing of the fluid plastics.
Similar difliculties in feeding and conveying in screw extruders of conventional construction are also observed in a particularly severe form during the processing of extremely pulverulent material having a very low .bulk weight, such as, for example, low-pressure crude polyethylene, certain types of emulsion polyvinyl chloride resins, polypropylene, and other plastics. In order to obviate the difficulties in feeding and conveying these non-fluid particles and powders, it is conventional to employ double or multiple screw extruders, or at least screw extruders having special feeding or tamping screw arrangements. As a result, complicated construction problems are encountered with these extruders and it is very diflicult to obtain satisfactory extrusions in terms of output and quality of products.
It is the object of this invention to provide a device for feeding and conveying non-fluid solid plastic particles and powders which is not subject to these deficiencies.
These objectives are obtained with a modification of the previously disclosed combination for extruding molten plastics. The screw extruder of this invention has an axial entrance pocket for the processing of thermo- Patented June 27, 1967 plastic synthetics which are fed to the inlet zone of the screw in a solid state of aggregation. The device of this invention is particularly suitable for processing plastics in a non-fluid form such as powders, chips, slices or other particles of low bulk weight. In order to ensure a reliable conveyance of the feed material to the screw, it is necessary that the latter be tightly enclosed in the entrance zone by the wall of the cylinder along a circular arc of from at least 180 to 270. Thus, the material fed to the extruder is pressed into the screw threads under the shearing, peeling and wedging effect of the entrance pocket and is subsequently transported immediately under force into the space enclosed by the cylinder wall. The screw threads are thereby completely filled. The largest cross-section of the entrance pocket is adjacent the filling port and is within the legs of a sector angle having the screw axis as its vertex, this angle being less than 180 and preferably from 45 to Experiments have confirmed that, surprisingly, this device eliminates the difliculties in the feeding and conveying process in a completely satisfactory manner, even when processing extremely pulverulent, powder-like material having a very low bulk weight. Suificiently high pressures can be obtained in the cylinder of the screw extruder without a special feed screw or a double screw arrangement, thus avoiding many disadvantages which are present in previously known devices.
For the processing of powders having a low bulk weight, it is desirable to make the inside width of the feed inlet approximately equal to or larger than the diameter of the screw, and preferably to provide an agitating device such as a stirrer in the feed inlet.
In the drawings several embodiments of the invention are illustrated.
FIGURE 1 shows a longitudinal section through the feed inlet zone and the portions of the screw extruder joining this zone on the left and on the right;
FIGURES 2 through 4 illustrate various cross-sectional shapes according to section 22 of FIGURE 1;
FIGURE 5 shows a further possible cross-sectional shape along section 5-5 of FIGURE 1;
FIGURES 6 through 11 show various positions and constructions of the entrance pocket; and
FIGURE 12 is a longitudinal section of an extruder with an agitator in the feed inlet.
Referring to FIGURE 1, the screw 3 is provided in the cylinder 1 which has a feed inlet 2. The cylinder section joining the entrance port is provided, according to this invention, with an entrance pocket 4 gradually tapering in the conveying direction. The radial distance between the upper surface of the entrance pocket defined by the screw jacket and the screw thread decreases constantly in the conveying direction, away from the feed inlet.
The breadth and height, as well as the length and/ or the slope of the upper surface of this axial entrance pocket can be specially adjusted to the bulk weight and flow properties of the material to be processed and to the friction between the contacting, loose particles of the plastic material. The length of the pocket, determined by the angle of inclination with respect to the screw axis, is of particular importance. This length should extend along several screw threads. For reasons of ease in the manufacture, as well as for functional reasons, the wall of the pocket can be a segment of a cylinder as shown in FIG- URES 6, 7 and 10, or a segment of a cone as shown in FIGURES 8, 9 and 11. The recess defined by the screw cylinder wall 1 can have the shape of a cylinder or cone having an axis which intersects the screw axis as shown in FIGURES 6, 7, 8, and 9, or which is askew therewith in the direction of rotation of the screw as shown in FIG- URES 10 and 11. Likewise, it is possible to fashion the surface of the pocket in an asymmetrical manner as a curved surface, for example, with the cross-section illustrated in FIGURE 5, wherein the radial distance from the screw thread to the upper surface of the pocket decreases in the direction of rotation of the screw. In each case, the decrease in volume of the entrance pocket in the direction of the screw axis or the conveying path can be adapted to the bulk weight of the plastic, and the axial direction of the recess can be adapted to the fluidity of the feed material. The decrease in volume can be increased for larger material bulk weights. The longitudinal dihedral angle between the screw axis and the axial direction of the recess can be increased for less fluid material.
The feed material conveyed by the first screw threads along the circumference thereof into the axial entrance pocket is pressed into the screw threads under the wedge effect of the pocket wall inclined toward the screw axis. The excess material swept aside at the cylinder wall is pressed into the screw thread sections which are only partially filled. For example, if the filling zone is completely filled an accumulation of material can be observed in the entrance pocket adapted to the inclined wall and having a tendency to move at right angles to the screw axis or backward. This accumulation is continuously depleted, but is increased again to the same extent by newly arriving material.
Because of the size of the entrance pocket, the inlet zone of the conveyor screw is extended along a relatively large distance in the axial direction, for at least the distance of two simple screw pitches. Thereby several screw threads are always simultaneously in a position to entrain the raw material, to conveyor the same into the cylinder space, and in this manner, to produce the pressure necessary for extruding the mass.
FIGURE 12 shows the screw extruder of this invention with an agitation device such as a stirrer for facilitating feeding of very low density powders into the extruder feed inlet 2.
Obviously, many modifications and variations of the invention as hereinabove set forth can be made without departing from the essence and scope thereof, and only such limitations should be applied as are indicated in the appended claims.
What is claimed is:
1. Ascrew extruder for the processing of non-freeflowing pulverous plastic solids of low bulkweight comprising a screw jacket means having an inlet end, an extruder screw disposed within said jacket means, a plastic material feed inlet means communicating with the inlet end of said jacket means, the inside width of said feed inlet having a size substantially at least as large as the diameter of the extruder screw, and an entrance pocket defined by the inner surface of the jacket means, said pocket extending from said feed inlet means for at least the length of a simple screw pitch in the axial direction of the screw, said pocket having its greatest cross-sectional area adjacent the feed inlet means, and the radial distance from the upper edge of the screw thread to the upper surface of the pocket decreasing constantly from adjacent the feed inlet means in the direction away from the feed inlet means; wherein the largest cross-sectional area of the entrance pocket adjacent the feed inlet means is within the legs of a sector angle having the screw axis as its vertex, the sector angle being within the range of from to 2. The screw extruder of claim 1 wherein the inside width of the feed inlet means in the axial direction of the screw is at least as large as two simple screw pitches.
3. The screw extruder of claim 1 wherein the entrance pocket is askew from the feed inlet means in the direction of rotation of the feed screw.
4. The screw extruder of claim 1 wherein the crosssectional shape of the entrance pocket is asymmetrical, and the radial distance from the screw thread to the upper surface of the pocket decreases in the direction of rotation of the screw.
5. The screw extruder of claim 1 comprising an agitation means extending into the feed inlet means.
References Cited UNITED STATES PATENTS 1,226,642 5/1917 Demovitsch.
1,923,678 8/1933 Lowell.
2,225,015 12/1940 Lebelle 2541 X 2,295,823 9/1942 Banigan et a1. 1812 X 2,422,722 6/1947 Fielitz 1812 2,611,941 9/1952 Leitl 1812 X 2,796,901 6/1957 Autio 146-184 WILLIAM J. STEPHENSON, Primary Examiner.

Claims (1)

1. A SCREW EXTRUDER FOR THE PROCESSING OF NON-FREE FLOWING PULVEROUS PLASTIC SOLIDS OF LOW BULKWEIGHT COMPRISING A SCREW JACKETE MEANS HAVING AN INLET END, AND EXTRUDER SCREW DISPOSED WITHIN SSAID JACKET MEANS, A PLASTIC MATERIAL FEED INLET MEANS COMMUNICATING WITH THE INLET END OF SAID JACKET MEANS, THE INSIDE WIDTH OF SAID FEED INLET HAVING A SIZE SUBSTANTIALLY AT LEAST AS LARGE AS THE DIAMETER OF THE EXTGRUDER SCREW, AND AN ENTRRANCE POCKET DEFINED BY THE INNER SURFACE OF THE JACKET MEANS, SAID POCKET EXTENDING FROM SAID FEED INLET MEANS FOR AT LEAST THE LENGTH OF A SIMPLE SCREW PITCH IN THE AXIAL DIRECTION OF THE SCREW, SAID POCKET HAVING ITS GREATEST CROSS-SECTIONAL AREA ADJACENT THE FEED INLET MEANS, AND THE RADIAL DISTANCE FROM THE UPPER EDGE OF THE SCREW THREAD TO THE UPPER SURFACE OF THE POCKET DECREASING CONSTANTLY FROM ADJACENT THE FEED INLET MEANS IN THE DIRECTION AWAY FROM THE FEED INLET MEANS; WHEREIN THE LARGEST CROSS-SECTIONAL AREA OF THE ENTRANCE POCKET ADJACENT THE FEED INLET MEANS IS WITHIN THE LEGS OF A SECTOR ANGLE HAVING THE SCREW AXIS AS ITS VERTEX, THE SECTOR ANGLE BEING WITHIN THE RANGE OF FROM 45* TO 90*.
US493099A 1964-11-06 1965-10-05 Extruder for processing solid thermoplastics Expired - Lifetime US3327347A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEB0079227 1964-11-06
DEB0082168 1965-05-29

Publications (1)

Publication Number Publication Date
US3327347A true US3327347A (en) 1967-06-27

Family

ID=25967301

Family Applications (2)

Application Number Title Priority Date Filing Date
US492518A Expired - Lifetime US3327348A (en) 1964-11-06 1965-10-04 Plastic melt extruder
US493099A Expired - Lifetime US3327347A (en) 1964-11-06 1965-10-05 Extruder for processing solid thermoplastics

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US492518A Expired - Lifetime US3327348A (en) 1964-11-06 1965-10-04 Plastic melt extruder

Country Status (9)

Country Link
US (2) US3327348A (en)
BE (1) BE671876A (en)
CH (1) CH427241A (en)
DE (2) DE1529803B2 (en)
DK (1) DK120919B (en)
ES (1) ES319226A1 (en)
GB (1) GB1103925A (en)
LU (1) LU49781A1 (en)
NL (1) NL6514337A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3398430A (en) * 1966-09-01 1968-08-27 Nrm Corp Extruder
US3703020A (en) * 1969-07-10 1972-11-21 Bliss & Laughlin Ind Anti-fouling caster, swivel-type
WO2004108379A1 (en) * 2003-06-05 2004-12-16 Helmut Bacher Device for preparation of plastic materials for recycling purposes

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4120050A (en) * 1977-03-17 1978-10-10 The French Oil Mill Machinery Company Devolatilizing vent
DE2738308A1 (en) * 1977-08-25 1979-03-08 Bayer Ag ELASTIC MOLDED BODY
DE3010825C2 (en) * 1980-03-21 1983-09-29 Plastik-Maschinenbau Gmbh & Co Kg Entwicklungsgesellschaft, 5489 Kelberg Processing machine for non-shredded thermoplastic plastic film webs
DE3320782C2 (en) * 1983-06-09 1985-10-31 Reifenhäuser GmbH & Co Maschinenfabrik, 5210 Troisdorf Plastic screw press
DE4421117C2 (en) * 1994-06-16 1996-08-14 Krauss Maffei Ag Device for loading injection molding and extruder units with viscous materials
JP4092444B2 (en) * 1997-12-04 2008-05-28 ミサワホーム株式会社 Molded product manufacturing method and kneading apparatus for molded product manufacturing
DE19928870C2 (en) * 1999-06-24 2003-10-02 Extrudex Kunststoffmaschinen G Single-screw extruder
DE102006029358A1 (en) * 2006-06-27 2008-01-03 Demag Ergotech Gmbh screw Press
JP5190500B2 (en) * 2010-09-30 2013-04-24 株式会社日本製鋼所 Plastic extrusion method and apparatus
JP6898295B2 (en) * 2018-12-27 2021-07-07 ファナック株式会社 Heating cylinder for resin melting of molding machine
CN110315746A (en) * 2019-08-05 2019-10-11 深圳市畅形增材科技有限公司 Small draw ratio extrusion screw rod and extrusion device
CN111483169A (en) * 2020-05-09 2020-08-04 济南大学 Compact forming equipment for carbon-based slow-release fertilizer

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1226642A (en) * 1916-09-20 1917-05-22 John Demovitsch Dough-cutting machine.
US1923678A (en) * 1931-11-14 1933-08-22 Benedict Stone Products Compan Bucket
US2225015A (en) * 1937-02-19 1940-12-17 Procedes Tech Const Method and means for producing concrete structures
US2295823A (en) * 1940-06-05 1942-09-15 Du Pont Artificial structure
US2422722A (en) * 1946-03-05 1947-06-24 Du Pont Extrusion apparatus
US2611941A (en) * 1948-11-29 1952-09-30 Leitl George Johann Felix Apparatus for the extrusion molding of concrete and like materials
US2796901A (en) * 1954-12-21 1957-06-25 Autio Paul Grinder for frozen materials

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1226642A (en) * 1916-09-20 1917-05-22 John Demovitsch Dough-cutting machine.
US1923678A (en) * 1931-11-14 1933-08-22 Benedict Stone Products Compan Bucket
US2225015A (en) * 1937-02-19 1940-12-17 Procedes Tech Const Method and means for producing concrete structures
US2295823A (en) * 1940-06-05 1942-09-15 Du Pont Artificial structure
US2422722A (en) * 1946-03-05 1947-06-24 Du Pont Extrusion apparatus
US2611941A (en) * 1948-11-29 1952-09-30 Leitl George Johann Felix Apparatus for the extrusion molding of concrete and like materials
US2796901A (en) * 1954-12-21 1957-06-25 Autio Paul Grinder for frozen materials

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3398430A (en) * 1966-09-01 1968-08-27 Nrm Corp Extruder
US3703020A (en) * 1969-07-10 1972-11-21 Bliss & Laughlin Ind Anti-fouling caster, swivel-type
WO2004108379A1 (en) * 2003-06-05 2004-12-16 Helmut Bacher Device for preparation of plastic materials for recycling purposes
US20060292259A1 (en) * 2003-06-05 2006-12-28 Helmut Bacher Device for preparation of plastic materials for recycling purposes
KR100744225B1 (en) 2003-06-05 2007-07-30 에레마 엔지니어링 리싸이클링 마쉬넨 운트 안라겐 게젤샤프트 엠. 베.하. Device for preparation of plastic materials for recycling purposes
US7309224B2 (en) 2003-06-05 2007-12-18 Erema Engineering Recycling Maschinen Und Anlagen Gesellschaft M.B.H. Device for preparation of plastic materials for recycling purposes
CN100430197C (en) * 2003-06-05 2008-11-05 奥地利埃瑞玛再生工程机械设备有限公司 Device for processing synthetic material for the purpose of recycling

Also Published As

Publication number Publication date
DE1529803B2 (en) 1972-02-17
ES319226A1 (en) 1966-05-16
US3327348A (en) 1967-06-27
LU49781A1 (en) 1966-01-05
DK120919B (en) 1971-08-02
DE1529803A1 (en) 1970-01-08
DE1529810A1 (en) 1970-06-18
GB1103925A (en) 1968-02-21
BE671876A (en) 1966-03-01
NL6514337A (en) 1966-05-09
DE1529810B2 (en) 1972-07-20
CH427241A (en) 1966-12-31

Similar Documents

Publication Publication Date Title
US3327347A (en) Extruder for processing solid thermoplastics
US3788612A (en) Mixing element for extruder screw
US3870284A (en) Extruder screws
US3867079A (en) Apparatus for extruding polymeric material
US2838794A (en) Extrusion apparatus
US3664795A (en) Screw extruders with dual section ejection zone
US4408888A (en) Double-worm extrusion press
US4047705A (en) Extruder with dual tapered screws
US11597118B2 (en) Device and method for the extrusion of thermo-mechanically deformable materials in bulk form, and compact screw extruder
KR100466291B1 (en) Device for pretreating and then plastifying or agglomerating plastics
GB1491162A (en) Preparation of expanded foodstuffs
US3976730A (en) Method of employing a high percentage of reground thermoplastic scrap resin in an extruder
US5375992A (en) Triple channel wave screw
US4053144A (en) Delta rotor through feed mixer
EP0105233B1 (en) Process for plasticization and pumping of low bulk density plastics
US8636497B2 (en) Extruder screw for a screw extruder
US4798472A (en) Extruder screw with balanced flights of different functional sections
US4659300A (en) Worm extruder for synthetic resin
US3559240A (en) Bulk plastic handling
US4063860A (en) Apparatus for employing a high percentage of reground thermoplastic scrap resin in an extruder
CN102922715A (en) Charging device and twin-screw extruder provided with the same
US3106746A (en) Extrusion head
US4642041A (en) Extruder screw for minimizing the opposing pressure flow
EP1207992B1 (en) Extruder screw
US6176606B1 (en) Extruder screw